Hazmat Regulations Pt2
Section-by-Section Review
We are incorporating by reference chapters II, III, IV, V and VI of the American Society of Mechanical Engineers (ASME) ``Pipeline Transportation Systems for Liquid Hydrocarbons and other Liquids,'' We are also updating the entry for the Compressed Gas Association's
Section 173.3
We are authorizing the use of salvage cylinders for overpacking a damaged or leaking cylinder containing hazardous materials other than Class 1 or 7 or acetylene. Hazmat salvage cylinders must be designed, constructed and marked in accordance with section VIII, division I of the ASME Code. Salvage cylinders are limited to a maximum capacity of 450 L (119 gallons). Contents of the damaged cylinder must be limited in pressure and volume so that if the cylinder totally discharges into the salvage cylinder, the pressure in the salvage cylinder will not exceed the maximum allowable working pressure (MAWP). We have authorized the use of salvage cylinders under exemptions for several years with a safe and satisfactory transportation experience.
Hazardous Materials in Classes 1 and 7 and acetylene were not authorized under the terms of these exemptions; therefore, we have no transportation experience and are not including them in this final rule. Salvage cylinders must be retested in accordance with the Compressed Gas Association's (CGA) Pamphlet C-6; however, because a salvage cylinder is not a DOT specification cylinder, the requirement for a Requalification Identification Number (RIN) does not apply.
In the NPRM, in paragraph (d)(2), we proposed that a ``salvage cylinder must have provisions for securely positioning the damaged cylinder therein.'' A commenter, Air Products, pointed out that not all cylinders have ``provisions'' for securing a damaged cylinder and asked RSPA to clarify what we meant. The intent of this requirement is to ensure that a damaged cylinder is secured in any manner that will prevent excessive motion during transportation; this could mean devices to secure the damaged cylinder or it could be compatible cushioning material that surrounds the damaged cylinder and restricts movement in the salvage cylinder. We revised the language in Sec. 173.3(d)(2) to reflect our intent.
In the NPRM, we proposed that the contents of the damaged cylinder must be limited in pressure and volume so that if totally discharged into the salvage cylinder, the pressure in the salvage cylinder will not exceed the MAWP at 21 [deg]C (70 [deg]F) for non-liquefied gases, or 55 [deg]C (131 [deg]F) for liquefied gases. A commenter stated that under this proposal certain liquefied gases, such as carbon dioxide and nitrous oxide liquid, could not be transported in currently available salvage cylinders unless controls are employed to prevent the pressure from exceeding the MAWP. The commenter suggested that one way to control the pressure in a salvage cylinder would be refrigeration or, alternatively in the case of short distances in extremely hot environments, the use of a canopy to shade a salvage cylinder being transported on an open trailer. Under the exemption program, neither of these methods was authorized to prevent exceeding the MAWP.
Instead of the pressure limits proposed in the NPRM, we amended paragraph (d)(4) to state that the contents of the damaged cylinder must be limited in pressure and volume so that if totally discharged into the salvage cylinder, the pressure in the salvage cylinder will not exceed 5/4 of the MAWP at 55 [deg]C (131 [deg]F). An exception to this is added for liquefied nitrous oxide and carbon dioxide cylinders. This is consistent with the general requirements for shipment of compressed gases in cylinders in Sec. 173.301.
The same commenter requested that we allow placement of the requalification marking on a metal plate affixed to the pressure vessel. In the NPRM, in paragraph (d)(13), we proposed that each requalified cylinder ``must be durably and legibly marked on the sidewall * * * '', however, we did not specify how the marking would be applied to the cylinder. Based on the commenter's request, we reconsidered various means of marking the cylinder and revised (d)(13) to allow the requalification marking to be placed on any portion of the upper end of the cylinder or on a metal plate permanently secured to the cylinder.
No stamping is authorized on the cylinder sidewall. This is consistent with the requalification markings in Sec. 180.213(b) and does not compromise the integrity of the cylinder.
In the NPRM we proposed that a salvage cylinder must be visually inspected and pressure tested every two years. The Chlorine Institute pointed out that in Sec. 180.209 of the HMR we require cylinder requalification every five years for most cylinders. The commenter stated that a ``two year interval is unwarranted and would result in an increased burden to the industry.'' We agree with the commenter and are adopting a requalification frequency of five years.
The Chlorine Institute also suggested that we should require all gaskets, valves and fittings be compatible with the hazardous materials overpacked in the salvage cylinder. We agree. Since all requirements for use of salvage cylinders are contained in Sec. 173.3(d), we are adding a new paragraph to include compatibility requirements for all gaskets, valves and fittings. We are also reformatting paragraph (d) for clarity.
More Hazmat Regulations to be added soon.